The present invention relates to a rifle bore cooler. In the prior art, it is known to provide a conduit with a ventilating fan to remove heat therefrom or supply ambient air thereto. In this regard U.S. Pat. Nos. 2,188,741 to Roberts and 4,641,571 to Anderson et al. are known to Applicant. Each of these references teaches a fan mounted on an opening of a ventilation flue and designed to be activated for ventilation purposes. The present invention differs from the teachings of these patents as being specifically designed of a small, portable nature, battery powered and designed with means specifically intended to removably affix the device over the end of a rifle barrel.